5,932 research outputs found

    NOViSE: a virtual natural orifice transluminal endoscopic surgery simulator

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    Purpose: Natural Orifice Transluminal Endoscopic Surgery (NOTES) is a novel technique in minimally invasive surgery whereby a flexible endoscope is inserted via a natural orifice to gain access to the abdominal cavity, leaving no external scars. This innovative use of flexible endoscopy creates many new challenges and is associated with a steep learning curve for clinicians. Methods: We developed NOViSE - the first force-feedback enabled virtual reality simulator for NOTES training supporting a flexible endoscope. The haptic device is custom built and the behaviour of the virtual flexible endoscope is based on an established theoretical framework – the Cosserat Theory of Elastic Rods. Results: We present the application of NOViSE to the simulation of a hybrid trans-gastric cholecystectomy procedure. Preliminary results of face, content and construct validation have previously shown that NOViSE delivers the required level of realism for training of endoscopic manipulation skills specific to NOTES Conclusions: VR simulation of NOTES procedures can contribute to surgical training and improve the educational experience without putting patients at risk, raising ethical issues or requiring expensive animal or cadaver facilities. In the context of an experimental technique, NOViSE could potentially facilitate NOTES development and contribute to its wider use by keeping practitioners up to date with this novel surgical technique. NOViSE is a first prototype and the initial results indicate that it provides promising foundations for further development

    Avionics test bed development plan

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    A development plan for a proposed avionics test bed facility for the early investigation and evaluation of new concepts for the control of large space structures, orbiter attached flex body experiments, and orbiter enhancements is presented. A distributed data processing facility that utilizes the current laboratory resources for the test bed development is outlined. Future studies required for implementation, the management system for project control, and the baseline system configuration are defined. A background analysis of the specific hardware system for the preliminary baseline avionics test bed system is included

    The NASA SBIR product catalog

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    The purpose of this catalog is to assist small business firms in making the community aware of products emerging from their efforts in the Small Business Innovation Research (SBIR) program. It contains descriptions of some products that have advanced into Phase 3 and others that are identified as prospective products. Both lists of products in this catalog are based on information supplied by NASA SBIR contractors in responding to an invitation to be represented in this document. Generally, all products suggested by the small firms were included in order to meet the goals of information exchange for SBIR results. Of the 444 SBIR contractors NASA queried, 137 provided information on 219 products. The catalog presents the product information in the technology areas listed in the table of contents. Within each area, the products are listed in alphabetical order by product name and are given identifying numbers. Also included is an alphabetical listing of the companies that have products described. This listing cross-references the product list and provides information on the business activity of each firm. In addition, there are three indexes: one a list of firms by states, one that lists the products according to NASA Centers that managed the SBIR projects, and one that lists the products by the relevant Technical Topics utilized in NASA's annual program solicitation under which each SBIR project was selected

    Assessing and augmenting SCADA cyber security: a survey of techniques

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    SCADA systems monitor and control critical infrastructures of national importance such as power generation and distribution, water supply, transportation networks, and manufacturing facilities. The pervasiveness, miniaturisations and declining costs of internet connectivity have transformed these systems from strictly isolated to highly interconnected networks. The connectivity provides immense benefits such as reliability, scalability and remote connectivity, but at the same time exposes an otherwise isolated and secure system, to global cyber security threats. This inevitable transformation to highly connected systems thus necessitates effective security safeguards to be in place as any compromise or downtime of SCADA systems can have severe economic, safety and security ramifications. One way to ensure vital asset protection is to adopt a viewpoint similar to an attacker to determine weaknesses and loopholes in defences. Such mind sets help to identify and fix potential breaches before their exploitation. This paper surveys tools and techniques to uncover SCADA system vulnerabilities. A comprehensive review of the selected approaches is provided along with their applicability

    Photoelastic Stress Analysis

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    Internet-based monitoring and controlling of real-time dynamic systems

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    The study in this report mainly focuses on the Internet-based Monitoring and Controlling of a Real-Time Dynamic System interfaced via a dedicated local computer. The main philosophy behind this study is to allow the remote user to conduct an Internet-based Remote Operation (I-bRO) for the dynamic system. The dynamic system has been defined as the system which has its parts interrelated in such a way that a change in one part necessarily affects other parts of the system [I]. In order to achieve this goal, the study has been conducted in a form of an on-line and real-time Virtual Laboratory (VL). Through this form of laboratory, a user can carry out the experiment, perform real-time monitoring and controlling operations of the experiment and collect real and live data from the experiment through the network link as the user was physically in the laboratory. The dynamic system that has been selected for the test-rig of this study is a 3-phase Induction Motor (IM) which is mechanically coupled with a DC-Dynamometer that acts as a variable load to the IM. This system is a common laboratory experiment in the study of the Electrical Engineering for both undergraduate and postgraduate students. The study covers both sides of the I-bRO; the hardware and the software. The hardware side includes the design and the development of a load control box that has been used to interface the DC-Dynamometer and consequently control it from the local computer. The software side covers the design and the development of the Virtual Instrumentation System (VIS) that has replaced successfully the physical Measurement and Test (M&T) instruments of the test-rig. Beside that, the software side includes the development of the internet remote front panel for the remote operation.Furthermore, the software side includes the development of the software that has been used to analyse the system during the I-bRO. In this study, the LabVTEW7 program has been used to design and develop the VIS and the Matlab program has bee used to aualyse the system performance for the remote operations. This study also addresses the issues and problems related to the intranet or the internet to be used as the network for data communication between the test-rig and remote users. This study has been carried out in different stages as follows: 1. Designing and development of the VIS. 2. Interfacing the test-rig apparatus with a local computer. 3. Upload the system from the local computer to the network. 4. Study the performance of the system on the network for the purpose of the remote operations controlled over the internet. The developed system of this study has been used for data acquisition, network communications, instruments monitoring and controlling applications. A user can execute on-line and in the real-time the developed VIS from any point in the university. Due to the fact that the university network is directly integrated to the main internet server. a remote user through the main internet server is able to perform I-bRO of the selected dynamic system. There are many factors associated with the network, the internet or the intranet, and have direct influences on the control system performance throughout the remote operations. The most dominant factors are the random time-delays and the data losses.These factors among others have to be addressed for a proper application of the I-bRO. For this reason, different cases and scenarios of the I-bRO have been investigated and simulated to study the affection of the network on the control system performance. The system is analysed under two control cases, closed loop with random time-delays and open loop when the internet server is disconnected and no communication between the input and the output of the system. In the first case, the closed loop, the internet server is assumed to be closed and subjected to random time-delays. In the second case, the internet server is subjected to random cut-off and thus opens the control loop. The results of both cases have been analysed and discussed. It has been found that, if the control system without the time-delays is stable, it remains stable even with small time-delays up to twenty seconds. This result is different from what has been shown in the literature

    3D-based Advanced Machine Service Support

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    In the face of today's unpredictable and fluctuating global market, there have been trends in industry towards wider adoption of more advanced and flexible new generation manufacturing systems. These have brought about new challenges to manufacturing equipment builders/suppliers in respect of satisfying ever-increasing customers' requirements for such advanced manufacturing systems. To stay competitive, in addition to supplying high quality equipment, machine builders/suppliers must also be capable of providing their customers with cost-effective, efficient and comprehensive service support, throughout the equipment's lifecycle. This research study has been motivated by the relatively unexplored potential of integrating 3D virtual technology with various machine service support tools/techniques to address the aforementioned challenges. The hypothesis formulated for this study is that a 3D-based virtual environment can be used as an integration platform to improve service support for new generation manufacturing systems. In order to ensure the rigour of the study, it has been initiated with a two-stage (iterative) literature review, consisting of: a preliminary review for the identification of practical problems/main issues related to the area of machine service support and in-depth reviews for the identification of research problems/questions and potential solutions. These were then followed by iterations of intensive research activities, consisting of: requirements identification, concept development, prototype implementation, testing and exploration, reflection and feedback. The process has been repeated and revised continuously until satisfactory results, required for answering the identified research problems/questions, were obtained. The main focus of this study is exploring how a 3D-based virtual environment can be used as an integration platform for supporting a more cost-effective and comprehensive strategy for improving service support for new generation manufacturing systems. One of the main outcomes of this study is the proposal of a conceptual framework for a novel 3D-based advanced machine service support strategy and a reference architecture for a corresponding service support system, for allowing machine builders/suppliers to: (1) provide more cost-effective remote machine maintenance support, and (2) provide more efficient and comprehensive extended service support during the equipment's life cycle. The proposed service support strategy advocates the tight integration of conventional (consisting of mainly machine monitoring, diagnostics, prognostics and maintenance action decision support) and extended (consisting of mainly machine re-configuration, upgrade and expansion support) service support functions. The proposed service support system is based on the integration of a 3D-based virtual environment with the equipment control system, a re-configurable automated service support system, coupled with a maintenance-support-tool/strategy support environment and an equipment re-configuration/upgrade/expansion support environment, in a network/lntenet framework. The basic concepts, potential benefits and limitations of the proposed strategy/ system have been explored via a prototype based on a laboratory-scale test bed. The prototype consists of a set of integrated modular network-ready software tools consisting of: (1) an integrated 20/30 visualisation and analysis module, (2) support tools library modules, (3) communication modules and (4) a set of modular and re-configurable automated data logging, maintenance and re-configuration support modules. A number of test cases based on various machine service support scenarios, have been conducted using the prototype. The experimentation has shown the potential and feasibility (technical implementation aspects) of the proposed 3D-based approach. This research study has made an original contribution to knowledge in the field of machine service support. It has contributed a novel approach of using a 3D-based virtual environment as an integration platform for improving the capability of machine builders/suppliers in providing more cost-effective and comprehensive machine service support for complex new generation manufacturing systems. Several important findings have resulted from this work in particular with respect to how various 20/30 visualisation environments are integrated with machine service support tools/techniques for improving service support for complex manufacturing systems. A number of aspects have also been identified for future work

    2004 Research Engineering Annual Report

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    Selected research and technology activities at Dryden Flight Research Center are summarized. These activities exemplify the Center's varied and productive research efforts
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